Using fetch_with_meta() on a list of elements to make multiple requests to a REST API

[olivierauverlot]

Hi,

I am encountering difficulties with the sqlpage.fetch_with_meta() function. For a project, I need to call a REST service that returns a list of identifiers. Subsequently, I need to use another REST service for each identifier to retrieve the data I require.
I have no issues calling the first service, which returns a JSON array. However, I am struggling to find a way to apply the fetch_with_meta() function to each element of this array.

What is a recommended approach to use fetch_with_meta() while iterating over a list of elements?

Best regards
Olivier

[lovasoa]

Unfortunately there is no nice built-in way to do this in SQLPage.

Either you do it from inside the database with https://github.com/pramsey/pgsql-http

Or you do it from an external script with sqlpage.exec.

[olivierauverlot]

Thank you for your response.

Unfortunately, I was expecting this answer. I have tried several approaches without success. It would be interesting to find a solution, as this is a common need when interfacing an SQLPage application with a REST API to cross-reference information with other applications in an information system.

Could we consider a function batch_fetch_with_meta() that takes a JSON array as a parameter, makes the different requests, and returns the result in a JSON-formatted string?

Something like this:

set request_1 = json_object(
    'method', 'POST',
    'url', 'https://sqlpage.free.beeceptor.com',
    'headers', json_object(
        'Content-Type', 'application/json',
        'Authorization', 'Bearer ' || sqlpage.environment_variable('API_TOKEN')
    ),
    'body', json_object(
        'key', 'value'
    )
);

set request_2 = json_object(
    'method', 'POST',
    'url', 'https://sqlpage.free.beeceptor.com',
    'headers', json_object(
        'Content-Type', 'application/json',
        'Authorization', 'Bearer ' || sqlpage.environment_variable('API_TOKEN')
    ),
    'body', json_object(
        'key', 'value'
    )
);

set responses = sqlpage.batch_fetch_with_meta(json_array($request_1, $request_2));

The response would be composed of JSON objects, each describing the result of one of the requests.